The present invention relates to hand held or hand mounted bar code scanners which provide for the entry of data by optical code reading or by keyboard entry and, more particularly, to a laser scanning terminal which combines a terminal for data entry and system configuration, a display, and a scan engine all in one unit. The single unit defines a hand held or hand mounted scanning terminal which will be collectively referred to hereinafter as a hand held scanning terminal.
The instant invention is especially suitable for providing a hand held data terminal which is battery operated and which may be used to gather data by manual entry of data and/or by operation of an optical reader of codes representing the data. All of these functions may be combined into a single scanning unit.
Typically, in portable scanners a light source such as a laser generates a scanning beam which is directed along a scanning path toward a bar code symbol for reflection from the symbol. A photodetector detects light of variable intensity reflected off of the symbol and generates electrical signals indicative of the detected light. These electrical signals are decoded into data for identifying the symbol.
The detailed design of bar code reading instruments, including the scanning circuitry, are described in U.S. Pat. No. 5,258,604, which was issued to James Behrens et al. on Nov. 2, 1993 and is entitled "Bar Code Scanner"; U.S. Pat. No. 5,237,161, which was issued to Scott R. Grodevant on Aug. 17, 1993 and is entitled "System for Automatically Reading Symbols, Such as Bar Codes, on Objects Which are Placed in the Detection Zone of a Symbol Reading Unit, Such as a Bar Code Scanner"; U.S. Pat. No. 5,212,371, which was issued to John A. Boles et al. on May 18, 1993 and is entitled "Hand Held Bar Code Scanner with Improved Aiming Means"; and U.S. Pat. No. 5,200,597, which was issued to Jay M. Eastman et al. on Apr. 6, 1993 and is entitled "Digitally Controlled System for Scanning and Reading Bar Codes." The entire contents of all four of these patents are incorporated herein by reference. A back of the hand type bar code scanning device is also shown and described in U.S. patent application Ser. No. 08/056,887, filed Apr. 2, 1993 by Chay La entitled "Non-Contact Actuated Trigger Apparatus for Bar Code Laser Scanner" which is also herein incorporated by reference. All four of these patents and the identified patent application are owned by PSC, Inc. (Webster, N.Y.) assignee of the present invention.
U.S. Pat. No. 5,250,790, which was issued to Boris Melitsky et al. on Oct. 5, 1993, entitled "Hand-Mounted Scanner with Automatic Manual Initiation of Reading Indicia," and U.S. Pat. No. 5,250,792, which was issued to Jerome Swartz et al. on Oct. 5, 1993, entitled "Portable Laser Diode Scanning Head," both assigned to Symbol Technologies, Inc. (Bohemia, N.Y.), disclose other conventional scanners.
Conventional prior art hand held scanning devices, particularly when mounted on the back of a hand or wrist, confront many difficult problems and disadvantages. The scanning devices must be made small in size to accommodate portable use. Further, when mounted on the back of a hand, it is necessary that the devices be of light-weight construction. To fulfil these requirements, many light weight portable units do not have display and keyboard functions. The usefulness of such devices is significantly limited since they cannot be easily reconfigured without attaching the portable scanner to some other device which includes input and display means. Further, without input keys, codes which cannot be optically read due to a label defect cannot be manually entered. One solution to this problem is to attach the device to other hardware. However, this additional hardware is typically quite bulky and defeats the primary purpose of a portable device.
Still other attempts have been made to incorporate a display and keyboard onto the device itself. FIG. 1A shows one such device where a scanner is mounted on a wrist. In FIG. 1A, a scanning beam 1 is generated by a scan engine located within the scanner 2. A small display 3 and input device 4 is incorporated into the scanner 2. The scanner of FIG. 1A is more particularly disclosed in U.S. Pat. No. 5,191,187. Numerous drawbacks are inherent in such a device. One such drawback is that the display and keyboard are necessarily small in order to be accommodated on the device shown. In other words, the volume available to accommodate the display and the keyboard is very limited. This makes it difficult for the operator to utilize the keys and limits the amount and size of data which can be displayed on the display. An additional drawback is that the input device is open to accidental actuation of the input keys as the arm of the operator is moved in the use of the device. Still another drawback of the device depicted in FIG. 1A is that the display is hard to see. The viewing angle for reading an LCD display is particularly critical. In order to achieve a desirable viewing angle in the device illustrated in FIG. 1A, the arm must be significantly rotated. As a result it is difficult to use the device's display while aiming the scanner.
Alternatively, the display 3 and input device 4 have been placed on the arm 5 of the operator as depicted in FIG. 1B. In FIG. 1B similar elements are referenced with like reference numerals. A cable 6 connects the scanner 2 to the display 3 and input device 4. This device is quite bulky and cumbersome to use. Further, the arm must be significantly rotated in order to operate the input device 4 and to achieve the optimum viewing angle for the LCD display 3.